No, it is not possible to force an unstable nucleus to decay by external means. The decay of a nucleus is a spontaneous process governed by the laws of quantum mechanics and nuclear physics. It occurs randomly and cannot be influenced or manipulated from outside the nucleus.
The decay of an unstable nucleus happens due to various processes such as alpha decay, beta decay, or gamma decay. These processes occur when the nucleus is in an energetically unfavorable state and undergoes a transformation to a more stable configuration. The specific decay mode and rate are determined by the properties of the particular nucleus and its internal dynamics.
While external factors like temperature, pressure, or radiation exposure can sometimes influence the rate of decay, they do not force the decay to occur. These factors can, at most, increase the probability of decay by altering the conditions in which the nucleus exists. However, the fundamental decay process itself remains spontaneous and cannot be externally controlled.